sustainability - SUNY College of Environmental Science and Forestry

Sustainability 2011 , 3 1875

Figure 3. EROI and drilling intensity for same year. Note inverse relation, especially after

1957 between drilling rate and EROI. Increased drilling does not necessarily generate more

oil produced because the EROI decreases with high drilling efforts after 1958.

Figure 4. EROI vs. drilling intensity for same year.

Energy input: The input of energy is dominated by the energy required to make equipment and then
natural gas used on site. There was a sharp peak in 1982 following the price increases of the 1970s and
a second, smaller peak in 2007 (Figure 5 and Table A-1 in Appendix).

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Drilling Intensity (Million Meters)

EROI

Year

Drilling Intensity

EROI

y = -0.0262x + 17.409

R^2 = 0.0384

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EROI

Million Meters Drilled

EROI

Linear (EROI)

G